Denon 3910 "ULTIMATE MOD!!" diy questions.

[kid vic]

   So I just got a DVD-3910 from my chef and as I was doing research on it I encountered this: http://www.underwoodhifi.com/2012/05/denon-dvd-3910.html popular mod (the one roughly half way down labeled "Ultimate Modification") and realized I really want to add tubes to this CD player. I was wondering how is it done and could someone proficient at DIY projects (a friend of mine) be able to do this, if so what would they need? The reason I'm looking DIY is because I'm pretty sure no one still offers this mod.